APA (7th ed.) Citation

Williams, Rowett, & Waller. (1996). Chronology of the 20th century. Helicon Publ. Ltd.

Chicago Style (17th ed.) Citation

Williams, Rowett, and Waller. Chronology of the 20th Century. Great Britain: Helicon Publ. Ltd, 1996.

MLA (8th ed.) Citation

Williams, et al. Chronology of the 20th Century. Helicon Publ. Ltd, 1996.